Material Technology - Dec 2013

Mechanical Engineering (Semester 4)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks. 1 (a) Discuss the Normalizing Heat Treatment process of steel. What is the purpose of normalizing. Give some applications of normalizing process.(10 marks) 1 (b) Define Fracture and give a brief classification of fracture. State Griffith's theory of brittle fracture and derive Griffith's equation.(10 marks) 2 (a) Define lattice defects and state causes of their formation. Discuss defects due to dislocations.(10 marks) 2 (b) Explain the purpose and process of tempering heat treatment. Explain different types of tempering process.(10 marks) 3 (a) State and explain slip mechanism of plastic deformation. What is critical resolved shear stress? Derive the expression for Critical resolved shear stress for deformation by slip.(10 marks) 3 (b) What is Diffusion Coating? Name its different methods. Discuss any one process of diffusion coating in details on the basis of principle, process, advantage and applications.(10 marks) 4 (a) Draw neat Iron-Iron Carbide Equilibrium diagram indicating all important temperature, phrases and composition.(10 marks) 4 (b) What is Nitriding? Explain different types of Nitriding processes. Explain the heat treatment before Nitriding.(10 marks) 5 (a) Write a note on Fatigue Failure. Explain thermal fatigue and corrosion fatigue.(10 marks) 5 (b) Explain the various transformation in Iron-Iron Carbide Equilibrium diagram.(10 marks) 6 (a) Draw and explain each stage of a Creep-curve. Explain Andrade's analysis of classical creep curve.(10 marks) 6 (b) What are Stainless Steel? Explain different types of Stainless Steels.(10 marks)

Write short notes on any four:-

7 (a) Retained Austenite.(5 marks) 7 (b) Ausforming Heat treatment process.(5 marks) 7 (c) Dispersion Hardening.(5 marks) 7 (d) Differentiate between Hot working and Cold working.(5 marks) 7 (e) Effect of alloying elements on Tempering.(5 marks) 7 (f) The solid solution.(5 marks)